healthcare enrollment verification of claims - sql

Question

All:
I'm trying to verify if a hospital stay should be covered based on enrollment data using SAS.
There are two tables:
"enr" : 2 years of a binary (0/1) if the patient was enrolled on that month.
data enr;
input id year jan feb mar apr may jun jul aug sep oct nov dec;
cards;
1 2018 0 0 0 1 1 0 0 0 0 0 0 1
1 2019 1 1 1 1 1 1 1 1 1 1 1 1
2 2018 1 1 0 0 1 1 1 1 1 1 1 1
2 2019 1 1 1 1 1 1 0 0 0 0 0 0
;
"clms" : id, admit_dt, discharge_dt, dr_id, cost
data clms;
input id admit_dt mmddyy10. #14dischrg_dt mmddyy10. code dr_id cost;
format admit_dt dischrg_dt mmddyy10.;
cards;
1 02/01/2019 02/06/2019 470 2 800
1 06/01/2019 06/15/2019 251 30 400
2 10/18/2018 10/22/2018 871 5 250
2 05/18/2019 05/22/2019 999 3 1000
;
For each "id" on the claims table, I wish to identify claims to be paid under the rule: for a paid claim, the patient must be enrolled in the 4 months prior and 4 months after the date of admission(admit_dt).
One of the tricky issues is the format of the months on the enrollment table(character, e.g."feb") differs from that of the admission date mmddyyy10 on the claims table.
Should I use an sql solution?

Answer 1

Transpose the enr data, compute which months are banded together, then perform a SQL join.
Example:
data enr_tall;
set enr;
array months jan feb mar apr may jun jul aug sep oct nov dec;
do i = 1 to 12;
month = mdy (i,1,year);
enrolled = months[i];
output;
end;
keep id month enrolled;
run;
data enr_tall_bands;
set enr_tall;
by id month;
retain count4;
if first.id then do;
count4 = 0;
band + 1;
end;
if ^first.id and not enrolled and count4 > 0 then do;
count4 = 0;
band + 1;
end;
if enrolled then do;
if count4 = 0 then band + 1;
count4 + 1;
end;
run;
proc sql;
create table news as
select
clms.*
, ( select count(distinct band) = 1 and min(enrolled) = 1
from enr_tall_bands as bands
where
bands.id = clms.id
& admit_dt between
intnx('month', month, -4)
and
intnx('month', month, 4)
) as
payable
from clms;